package org.fb.client;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import org.fb.dto.RpcRequest;
import org.fb.dto.RpcResponse;
import org.fb.handler.UserClientHandler;
import org.fb.utils.JSONSerializer;
import org.fb.utils.RpcDecoder;
import org.fb.utils.RpcEncoder;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.UUID;
import java.util.concurrent.*;

/**
 * @author fanbo@imoran.net
 * @date 2021/2/6 20:58
 */
public class RpcConsumer {

    /**
     * 1.创建一个线程池对象  -- 它要处理我们自定义事件
     */
    private static ExecutorService executorService = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());

    /**
     * 2.声明一个自定义事件处理器  UserClientHandler
     */
    private static UserClientHandler userClientHandler;

    /**
     * 3.编写方法,初始化客户端  ( 创建连接池  bootStrap  设置bootstrap  连接服务器)
     */
    public static void initClient() throws InterruptedException {
        //1) 初始化UserClientHandler
        userClientHandler = new UserClientHandler();
        //2)创建连接池对象
        NioEventLoopGroup group = new NioEventLoopGroup();
        //3)创建客户端的引导对象
        Bootstrap bootstrap = new Bootstrap();
        //4)配置启动引导对象
        bootstrap.group(group)
                //设置通道为NIO
                .channel(NioSocketChannel.class)
                //设置请求协议为TCP
                .option(ChannelOption.TCP_NODELAY, true)
                //监听channel 并初始化
                .handler(new ChannelInitializer<SocketChannel>() {
                    @Override
                    protected void initChannel(SocketChannel socketChannel) throws Exception {
                        //获取ChannelPipeline
                        ChannelPipeline pipeline = socketChannel.pipeline();
                        //设置编码
                        pipeline.addLast(new RpcEncoder(RpcRequest.class, new JSONSerializer()));
                        pipeline.addLast(new RpcDecoder(RpcResponse.class, new JSONSerializer()));

                        //添加自定义事件处理器
                        pipeline.addLast(userClientHandler);
                    }
                });
        //5)连接服务端
        bootstrap.connect("127.0.0.1", 8999).sync();
    }

    /**
     * 4.编写一个方法,使用JDK的动态代理创建对象
     * serviceClass 接口类型,根据哪个接口生成子类代理对象;   providerParam :  "UserService#sayHello#"
     */
    public static Object createProxy(Class<?> serviceClass, final String providerParam) {
        return Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(), new Class[]{serviceClass}, new InvocationHandler() {
            @Override
            public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                //1)初始化客户端client
                if(userClientHandler == null) {
                    initClient();
                }

                //2)给UserClientHandler 设置param参数
                RpcRequest rpcRequest = new RpcRequest();
                String messageId = UUID.randomUUID().toString();
                rpcRequest.setRequestId(messageId);
                System.out.println("messageId: " + messageId);
                String[] classNameAndMethod = providerParam.split("#");
                rpcRequest.setClassName(serviceClass.getName());
                rpcRequest.setMethodName(classNameAndMethod[1]);
                rpcRequest.setParameters(args);
                rpcRequest.setParameterTypes(new Class[]{String.class});
                userClientHandler.setParam(rpcRequest);

                //3).使用线程池,开启一个线程处理处理call() 写操作,并返回结果
                //4)return 结果
                return executorService.submit(userClientHandler).get();
            }
        });
    }
}

